query_question: An ideal vapor-compression refrigeration cycle that uses refrigerant-134a as its working fluid maintains a condenser at 800 kPa and the evaporator at 212°C. Determine this system's COP and the amount of power required to service a 150 kW cooling load.<image 1>
options: ['4.07, 31.8 kW', '4.97, 33.8 kW', '4.87, 30.8 kW']
demo_question_list: An ideal gas taken round the cycle ABCA as shown in PV diagram<image 1>.The work done during the cycle
  A. PV
  B. PV/2
  C. 2PV
  D. PV/3
  
  Answer with the option's letter from the given choices directly. The long pipe in Fig. 3.133 is filled with water at 20°C. When valve A is closed, p1 - p2 = 75 kPa. When the valve is open and water flows at 500 m^3/h, p_1 - p_2=160 kPa. What is the friction head loss between 1 and 2, in m, for the flowing condition? <image 1>
  A. 7.6 m
  B. 9.2 m
  C. 8.7 m
  
  Answer with the option's letter from the given choices directly. An insulated piston-cylinder device contains 5 L of saturated liquid water at a constant pressure of 175 kPa. Water is stirred by a paddle wheel while a current of 8 A flows for 45 min through a resistor placed in the water. If one-half of the liquid is evaporated during this constant-pressure process and the paddle-wheel work amounts to 400 kJ, determine the voltage of the source. Also, show the process on a P-v diagram with respect to saturation lines. <image 1>
  A. 204 V
  B. 224 V
  C. 244 V
  
  Answer with the option's letter from the given choices directly. The 3-arm lawn sprinkler of Fig. P3.114 receives 20°C water through the center at 2.7 m^3/hr. If collar friction is neglected, what is the steady rotation rate in rev/min for $\theta $ = 40°? <image 1>
  A. 317 rev/min
  B. 414 rev/min
  C. 400 rev/min
  
  Answer with the option's letter from the given choices directly.